High speed telegraph transmitter



April 26, 1932. H. CHIREIX HIGH SPEED TELEGRAPH TRANSMITTER Filed June30, 1927 E w M sum 5 khxhQNk ii: M 5 H T i n; 5255 h5w ki mi uw-wwkk lawn. w v QWHUW ,ooooooooo.oooooooooooo.ooooo oooooooooooooooooooood N 0 Omum O v v INVENTOR HENRI tHlRElx A ORNEY Patented Apr. 26, i932 u 'ranstatus jPfATEMT- LQFEEQE HENRI 'dirmnrx,or

V mem'srnnn rn nnenarn Application fllecl June 30, 1927, Serial No.202,484, mid inFrance J'uly 9', 1926.

. The object of the present invention isto provide means whereby a linecurrent may be sent according to the rhythm of Morse-code signals, forinstance, at an extremely rapid rate, at all events, more rapidly thanhas been possible by mechanical systems involvingfinertia in relays,etc. i

Systems known in the prior art consist in the use of a perforated stripor band allow-- 10 ing of the passage at intervals'of a beam of lightcaused to impinge upon a photo-electriccell. Systems of this kindinvolve the drawback that they require a whole set of optical devices, aphoto-electric cell and an amplifier folri amplifying the currentsproduced by the ce Now, the system forming the sub'ect-matter of thepresent invention consists: asically is active; The dielectric mayconsist of air or of a material possessing a dielectric constant higherthan air. The result is a varia-- tion in capacity and consequently avariation in the ensuin frequency. To carry this method into e ect aswill be understood, it is necessary that the frequencies of the saidsmall oscillators should be very high in such a way that the actionunder consideration 40 may result in a variation in beat frequencychosen in the following way: When a solid portion of the band (soliddielectric) is placedopposite the electrodes of the small auxiliarycondenser, the beat frequency is vmade very low, while when theperforated band presents a hole opposite the electrodes of the smallauxiliar condenser, then the beat frequency is 'shi ed into the range ofmusicahnotes. This frequency is then modof several hundred periods.According to a. preferable plan, arrangements may then becrately'amplified by the aid. of trans formers. provided with a limited numberof turns sdthat the grave-note periods may not rent is detected. Hence,it will be seen that our cut is available at the output end of theampifier only in the presence of one or two be transmitted, and then,if. desired, the cur- By paying out the-perforated.

A better understandingof the invention willbe had from'the followingdetailed description and therefrom when read in connection with thedrawings-in which,

Figure 1 shows a perforated tape be used to vary the capacii; of thecondenser in 'one of the oscillation generators,

Figure 2 shows a modification of the perforated tape shown in Figure 1Figure 3 shows a circuit arrangement including the oscillationgenerators and the amplifiers, h

Fi ure 4- shows the relation between the v'aria le frequency oscillationgenerator and thle frequency controllingperfiorated tape, w ile,

Figure 4a shows a modification of the condenser arrangement of Figure45.

fora'tions of the band may be arranged and chosen irgggdifierent ways.For instance, it is practicalfy recommendable to use for the Morse code,and in combination with existent perforators, a band of the kind shownin Figure 1.

Referrin to 1 re 1, 1 stands for the forward-feed 0168?; the tape; 2,the perforations indicating dots; and 3, the perforationsindicatingdashes. 4c and 5 finally. indicate the projections of one ofthe electrodes of two small auxiliary condensers connected in passageofa dot such as 2, though the varia- 4 u, so The plates ofhe condenserand the pera bridge circuit input which would be adtape.

tion in capacity remains the same regardless of whether dashes or dotsare dealt with.

As shown in Figure 2, it is also possible to use a special tape directlyperforated in Morse signals, the dashes 3' corresponding to a longerperforation than the dots 2. 1 indicates again the tape feed holes,while 4' shows a projection of an armature of an auxiliary condenser.

Figure 3 shows a circuit arrangement which ma be used to carry out myinvention. Tu e10 produces oscillations of a fixed frequency F. Tube 12produces oscillations of a frequency H which depends upon the capacityamount of C.-- The capacity of C in turn depends upon the perforationsof the Both F and are Very high frequency so that the slight variationin C will produce a considerable percentage variation in the differencebetween H and F. This difference HF need not necessarily be audible.

i The only requirement is that when an unperforated part of the tape ispassing, the difference I-I-F should be sufficiently out of tune withthe, amplifier so that nothing happens, but when a perforation passes,the difference H-F should be that to which the amplifier is tuned.Tube'13 is the tube which produces the difference frequency and I haveshown vantageous in practice as it prevents the oscillators 10 and 12from influencing each others frequency. The resistance capacity 16 andapplied to the grid of tube 17 which,

combination Z is the element required to balance the bridge and itsvalue is determined by the grid filament impedance of the tube.Oscillator 10 is coupled to circuit F of tube 13 while oscillator 12iscoupled to circuit H. The beat frequency HF is selected by the tunedcircuit in the plate of tube 13 and amplified by tube 14 and detected bytube 15. As each dot in the tape passes the condenser there will be anincrease of current through the resistance in the plate circuit ofdetector 15.

The pulses of .voltage are amplified by tube acts as the modulator tubeof a Heising system of modulation of which tube -18 is the oscillatorwhich is adjusted to a frequency S which is the frequency at which theradio transmission is to be efiected. The oscillator 18 is then coupledto the input of a two stage amplifier which vfeeds the antenna. Thisamplifier shown for convenience at the bottom of Figure 3 includes aninductance S couled to the oscillator 18 and included in the i 3' "inputcircuit of an amplifier 19 the output circuit of which is in turncoupled to an yes.

inductance 21in the input circuit of a second amplifier'20. The secondamplifier 20 is coupled by means of an inductance 22 in its out-'circuit to the load circuit which for purposes of illustration has beenshown to be a radiating circuit.

Figure '4 show'sgin detail a variable freby a main capacity and acapacity C which is variable in accordance 'with the present inventionby changing the dielectric between the plates 4, 4 thereof. As pointedout above, the capacity of the condenser C is altered in the inventionby altering the dielectric between the plates 4, 4. This is accomplishedby passing the perforated tape between the condenser plates. Since thedielectric constant of air is different than the dielectric constant ofthe material of which the tape is composed, the capacity of thecondenser C will be varied as the dielectric thereof is composedalternately of air and of the material between the perforations in thetape. In Figure 4, the tape has been shown to be similar to the tapeillustrated in Figure 2.

In case the tape shown in Figure 1 is used to control the frequency ofthe variable frequency generator 12, a condenser arrangement asillustrated in Figure 4a is used. As will be seen in Figure 4a, thecondenser C comprises plates 4, 5 cooperating with ure 1 to control thefrequency of the oscillation generator 12.

It will be understood that the invention is capable of a great number ofmodifications,

' plates 4, 5' and with the tape shown in Fighaving coupled input andoutput circuits, a

second thermionic oscillation generator having coupled input and outputcircuits, means in the, piput circuit of said last namedoscillation-generator to tune said last named oscillation generator to afrequency differing from the frequency of the oscillations generated bysaid first named oscillation generator, an auxiliary capacity connectedin parallel with said tuning means, means for varying the dielectricbetween the electrodes of said auxiliary capacity in accordance with thesignal to be transmitted, and a utilizing circuit connected toboth ofsaid oscillation generators.

2. In radio communication apparatus, a source of oscillations ofconstant frequency, means for producing oscillations at a frequencydiffering from the frequency of said frequency amplifier connected withsaid combining circuit, signal translating means connected with saidbeat frequency amplifier, means for modulating the oscillations producedby said thermionic oscillation generator comprisinlgan auxiliarycapacity connected in para 1' with 'said tuning capacity and means forvarying the dielectric of and auxiliary capacity at slgnal frequency.

3. A telegra h, --transmitter including a thermionic osci lationgenerator having coupled input and output circuits, a sec on theremionic oscillation generator having coupled input and output circuits,capacity means in I m the input circuit of said last named oscilla tiongenerator-to tune said l ast named oscillation generator to a frequencydifiering from the frequency of the'oscillations generated by said firstnamed oscillation generator,'a n auxiliary capacity connected invparallel with said first named capacit means for varying the dielectricbetween the electrodes of said auxiliary capacity 'in accordance withthe signal to be transmitted, a thermionic relay having its inputcircuit coupled to bothiof said generators and its output circuitcoupled to a selective amplifier tuned to the beat frequency, and atransmitten connected ,with said amplifier. r

4. In radio communication apparatus, a

source of oscillations of constant frequency, thermionic means forproducing oscillations at a frequency difiering from the frequency ofsaid first named source compiising a thermionic tube having coupledinput and output circuits, capacity means fortuning said input circuit,a combining circuit connected with both of said oscillation generators,a beat frequency amplifier connected with said combining circuit, signaltranslating means connected with said beat frequency amplifier, an OS.-cillator connected with said signal translating means, a work circuitconnected with said 7 oscillator, means for modulating the oscilla- 4otions produced by said thermionic oscillation generator comprising anauxiliary capacity connected in parallel with said tuning capacity, andmeans for varying the dielectric of said auxiliary capacity at signalfrequency.

HENRI CHIREIX.

